Walk-in cold rooms, such as walk-in coolers, freezers, or other refrigerated environments, are common in various industries, including supermarkets and grocery stores, commercial kitchens, and other food service facilities. They typically have one or more access doors for entry and exit.
These doors are heavy and thus a common problem that may occur over time is door sag, which may cause the door not to open freely as it drags against the underlying floor or be properly locked or sealed as it does not fully close. The sag is caused by hinge wear, structural shifting due to temperature cycling, impacts, abuse, poor design of the door and frame, or the hinges shifting on the mounting screws. Sag is difficult to overcome without extensive repair work, such as the removal and remounting of the hinges or the replacement of the door and frame. For the replacement, adjustment or cleaning of the hinge the NSF prefers that the hinge be a “lift-off” type to allow the door and the enclosure to be cleaned by lifting it off the hinges and hosing down the door assembly.
A problem associated with these “lift-off” type hinges is that the hinge spring is designed to move the cam past the point of door closure to ensure a complete closing of the door, this may be referred to as an over-closure angle between the hinge strap and hinge flange. As a result of the over-closure of the cam when the door is taken off the hinge, the subsequent replacement of the door upon the hinge flange does not always result in the proper alignment of the hinge strap upon the hinge flange. This problem can result in the poor closure function of the hinge, the misalignment of the hinge components, and/or damage to the hinge.
Another problem associated with these hinges is that they are made of metal which when contacted with a cart or other loading equipment may become scratched, scarred, dented or otherwise damages both physically and aesthetically. Additionally, this accidental contact may result in causing damage to the cart or other loading equipment. Some hinges are made of a combination of metal components with a hard plastic covering, as shown in U.S. Pat. No. 7,870,642. These hard plastic covers however may crack or break upon collision with a cart or the like.
Accordingly, there is a need in the art for a hinge that will allow for the door to be lifted off easily, which does not promote door sag, which allows small adjustments to the hinge, and which also reduces damage to the hinge or the a contacting piece of equipment should an accidental contact or collision occur. It is to the provision of such therefore that the present invention is primarily directed.